Method of applying plasterlike material to structures



i This invention; is to: improvements in or rehatingtc a method of applying: a .rendermg; of plaster-like materiaLto stmctures, 11;. It". is. well known to apply cementitious. mixes to: thasmfaces; of structures, suchas. walls and ceilings, by trowelling or by hand, a mixture of sand, cement and water of a suitable consistency. finch methods are slow.. require considerable I skill and arexthereiore expensive. .Many efiorts have been made to apply such ra like sprayins. devices but such. metho have, in genral, not proved successful due to the tendency of the constituents of the mixtures to separate; f, ;.A;J'.\ ,object oi the present invention. is to -pro-- a method of applying such renderings which simple, effective and cheap and. which will v prevent the separationot the constituents of the According to the present. invention, therefore,- there is provideda method of applying a ren- U dering of plaster-like material to the surfaces of structures which comprises forming a plaster a wetting, frothing or dispersing agent the mix in an amo n o e herein means a consistency which is sufliciently' fluid to allow the mix toflow freely through the pipe-line and nozzle of the spraying apparatus andyet is sufficiently self-supporting to be cawhich it has been applied.

The preferred. increase in volume is from about 45w570 and is readily achieved by vigorous 'agitationTii the mix, advantageously in a whiskpable of remaining in position on the to ing machine specially designed for the purpose of aerating concrete mixes. Any other conven-- ient method, however, for achieving the incorporation oi the air in. the mix may-be adopted. The proportion of water in the mix may be variedzin accordance with the degree of volume increase. which is a required, for: example; for a smaller volume. increase during aeration, the proportion of water may be less than would be required for a greater volume increase on aeraesbressionrmwermw-a usedmerein in ivmrnon'of APPLYING PLAsrEnLmnk MATERIAL TO STRUCTURES V Eugene. Mellon .Farnham, England, assignor j Gheecol. Processes Limited, .London, Englandt, i

V aBritish. company, and Aerocem Limited, Lon- I i 1'1 dnniE s ndam-itish compa v r NmDrawints Application November as; 1941;

" Serial Nm 8,31% In Greatliritain Sentcm- Section Lmucnw'amums,ms?

- v Patent-expires September 19,1966

indicate the several sulphate plasters, n m ures or or plaster or both'iwith cements. i A'ccofdih'g'mreof the. inventidmrtherm fore, thev plaster mix comprises acmix a? sand, cement and water, the ratio. at sand to. cement being not greater than 3:1. The preferred ratio ot'sand to cement is from. .111 to 221mm: the actual ratio selected willv depend upon the particular purpose for which the rendering is required.

The ratio of water to cement: will vary depending upon the degree of volume increase. which is desired. For avnlumeincrease of about 50% .the weight ratio of water to cement may be from about. 0.55. to about 0.65;; preferably about me, the, figure beingcalculated with referencetzrthe final mix, that is; takineintcr consideration the moisture content 01! thesand used. 1'. I haveiound. that when operating-in accord- 2 r ance with thepresent invention, the plaster-like .material can readily be sprayed througlt' any suitable spraying apparatus operated byair-pressure provided, of course, that theoriflce-o! the spraygun is sufliciently large to permit. of the 2F. passage of the largest of the. said particles present in the mix. Spray guns which can be used for. the spraying of paint. and like liquid compositions can be employed, butlpreferably the spraying device is one which .has uninterrupted passages, preferably straight. and preferablybeing provided with conical pressure ports converging towards the point of discharge; 51

It will be understood that the: wetting, nothmg or dispersing" agent employed is'oi' such a character thatit is not-precipitated or destroyed by any alkali, calcium or'magnesium' compounds present in the mix or liberated by a component thereof. It will be appreciated that so long as the wettin frothing or dispensingagent re- Y u g:

suitable wetting" ent-beingthe material sold .underthe trade-marl: Cheexol' XX" the-word sci .fCheecol being-a registeredtrade-mai-E'i cheecol" comprises a mixture or the was: 91

The "GthOdxIthG- presentv invention; may, in some circumstances; be not operated prosince. a cellular rendernig on thesuriao otthe YEXAMINEINRA h described in Example 2.

structure to which it has been applied, such cellular rendering being particularly advantageous where thermal and sound insulation is required.

The following examples illustrate the production of plaster mixes which are suitable for application by means of a spray gun:

Example 1.-A mix was prepared by mixing together approximately 96 lbs. of coarse sand, approximately 36 lbs. of hydrated lime, approximately 4 gallons of water and, when these materials had been mixed together, 25 fluid ounces of the wetting agent sold under the trade name "Cheecol XX were added to the mix andthis was then vigorously agitated in a whisking machine for 4 minutes.

The mix was readily sprayable to form a good even rendering on a wall surface.

Example 2.A standard plaster mix was prepared by stirring the calcium sulphate sold under the trade name Syrupite into 1 /2 gallons of .--wat r, the amount of the plaster being such that the mix had a creamy consistency as referred to above. 2% fluid ounces of a wetting agent sold under the trade name "Cheecol XX were then added and the plaster mix vigorously agitated for 2 minutes as in Example 1, this mix was readily sprayable.

Example 3.A first coat of plaster was prepared by mixing 1 /2 parts of sand, 1 /2 parts of the-plaster sold under the trade name Paristone with sumcient water to form a mix of a creamy consistency, whereafter the wetting agent-sold -'under the trade name Cheecol 2Q? was added so that the mix contained about 0.1% by weight of wetting agent calculated upon the weight of plaster. A second plaster mix was prepared in substantially the same way as the foregoing plaster mix but containing 2 parts of sand to 1 'of plaster, whilst a third plaster mix was prepared utilising the same plaster as in the two preceding'mixesr this plaster was prepared as The first mix was used as an initial rendering, the second mix was used as a second rendering and the third mix was used as a final finishing rendering.

Example 4.-A plaster mixwas prepared by mixing together 64 lbs. sand, 14 lbs. of hydrated lime, 8 lbs. of Portland cement and 1 gallon of water; to this mix there was added 10 fluid ounces .woi the wetting agent sold under the trade name Cheecol XX" and the mix was then given a 4 minutes-whisk as described in Example 1.

This plaster mix is particularly suitable as an internal rendering to receive a top rendering of the plaster described in Example 2. Example 5.A mix was prepared by mixing to- .gether 96 lbs. sand, 14 lbs. of hydratedlime, 12

- together approximately 96 lbs. of coarse sand, ap-

proximately 36 lbs. of Portland cement and approximately 4 gallons of water, and when these materials had been mixed together, 25 fluid ounces of the wetting agent sold under the trade .name Cheecol XX were added to the mix and this was then vigorously agitated in a whisking machine for minutes. I a

The mix was readily sprayableto form a good even rendering on a wall surface.

E All the mixes'referredto in the foregoing .ex--

amples are capable of being sprayed to form a satisfactory rendering upon a wall surface or the like and it is to be understood that the invention is not limited to the particular specific details of these examples.

I claim:

1. A method of applying a rendering of plaster which comprises forming a plaster mix, adding a frothing agent to said mix in an amount of from 0.001% to ,0.5% by weight of the settable s wsa 0 ixt'o rm a mass of a consis ency and fineness of particles such that it is self-supporting but suiflciently fluid to flow through a pipe-line and through the spray nozzle of a spray gun suitable for spraying paint, introducing air into the mass to aerate it to efiect a volume increase of at least 20% and to form a stable, cellular mass and spraying the aerated mix on to the surface to be rendered by means of air pressure. f

2. A method according to claim 1 wherein air is introduced into said mass until a volume increase of from 45% to 55% is achieved.

3. A method according to claim 1 wherein said plaster mix comprises sand, Portland cement and water, the ratio of sand to cement bein not greater than 3:1. 4. A method according to claim 3 wherein the ratio of sand to cement is between 1 :1 and 2:1 and the ratio of water to cement is between 0.55:1 and 0.65:1.

5. A method according to claim 1 wherein said plaster mix comprises hydrated lime as the settable solid component of the mix.

6. A method according to claim 1 wherein said laster mix comprises 0 m sulphate plaster setaesoi '7. A metho according to claim erin said irothing agent is an alkali metal salt of a sulphated higher alcohol.

8. A method of applying a rendering of plaster to the surfaces of structures which comprises forming a mix of sand, cement, water and a irothing agent of a consistency and fineness of particles such that it is self-supporting butsumciently fluid to flow through a pipe-line and through the spray nozzle of a spray gun suitable for spraying paint, the ratio of sand to cement being not greater than 3:1 the weight ratio of total water to cement being from 0.55:1' to 0.65:1 and the amount of said frothing agent being from 0.001% to 0.5% by weight of the cement, introducing air into the mix to effect an increase in'volume ofirom 45% to 55% and to form a stable cellular mix and spraying the aerated mix on to the surface to be rendered by means of air pressure.

9. A method according to claim 8 wherein said frothing agent is an alkali metal salt of a sulphated higher alcohol.

EUGENE MOLLO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 

1. A METHOD OF APPLYING A RENDERING OF PLASTER WHICH COMPRISES FORMING A PLATER MIX, ADDING A FROTHING AGENT TO SAID MIX IN AN AMOUNT OF FROM 0.001% TO 0.5% BY WEIGHT OF THE SETTABLE SOLID COMPONENT OF SAID MIX TO FORM A MASS OF A CONSISTENCY AND FINESS OF PARTICLES SUCH THAT IT IS SELF-SUPPORTING BUT SUFFICIENTLY FLUID TO FLOW THROUGH A PIPE-LINE AND THROUGH THE SPRAY NOZZLE OF A SPRAY GUN SUITABLE FOR SPRAYING PAINT, INTRODUCING AIR INTO THE MASS TO AERATE IT TO EFFECT A VOLUME INCREASE OF AT LEAST 20% AND TO FORM A STABLE, CELLLAR MASS AND SPRAYING THE AERATED MIX ON THE SURFACE TO BE RENDERED BY MEANS OF AIR PRESSURE. 